#### 38 Questions about the Binary Tree to Ask in an Interview (With Sample Answers)

A binary tree lets you store data in a hierarchy, while a list is the best way to store data in a straight line. As a programmer, it’s important to know how to answer questions about binary trees when you’re getting ready for coding interviews. If you know how to answer the most common binary tree interview questions, you may be able to impress the hiring manager and get the job. This article looks at 38 common interview questions about binary trees to help you get ready for your next one.38 Questions about the Binary Tree

**General interview questions**

A hiring manager will usually start an interview by asking general questions to learn more about a candidate. Here, you could be asked about your work ethic or what you want to do with your career. Here are 14 examples of the types of general questions you might be asked at a binary tree interview:

- How did you hear about this job opening?
- What’s something interesting you can tell us about yourself?
- What makes you want this job?
- Why did you want to work for our business?
- Do you prefer to work alone or in a group?
- How do you deal with stress or situations that put you under a lot of pressure?
- How do you choose the first thing to do?
- What are some of your career goals, and how do you plan to achieve them?
- What do you think we could do to change or improve our business?
- If you were an animal, which one would you be?
- What do they need to know about you that’s not on your resume?
- Do more than one company want to talk to you?
- What kind of environment do you like to work in?
- Have you ever had a boss whose decision you didn’t agree with?

**Questions about your past and your experience**

In the second part of the interview, you will be asked about your work history and background to make sure you’re qualified. These questions are also asked by hiring managers to find out what you’ve done, how well you did on past projects, and how well you did at your previous jobs. Based on what you know about the company, try to give answers that are directly related to the job opening. Here are 11 questions about your experience and background that you can look over and think about how you might answer them:

- What is the purpose of a binary tree?
- What is the purpose of a binary heap?
- What do you do first when you create a new binary tree?
- Can you explain some projects you have on your resume?
- What else can you say about the jobs you’ve held?
- What’s your favorite way to write code?
- What is the best thing you’ve done on the job?
- What did your last job do to help you get better at what you do?
- What do you dislike most about binary trees?
- What does a binary search tree look like?
- How do you keep up with what’s happening and what’s popular in your field?

**In-depth questions**

Hiring managers ask you in-depth interview questions to find out more about your behavior, attitude, and way of thinking. When you answer, give details to show that you know what your role is and what the industry is like. Here are some examples of the types of detailed questions you might be asked in a binary tree interview:

- How do you use your favorite language to find a binary tree’s lowest common ancestor?
- Can you put algorithms for going through trees into groups?
- What happens when you add or take away nodes from a red-black tree?
- Most of the time, people set up a priority queue like this:
- Why does it matter that a tree is balanced?
- Why is it better to use a binary search tree instead of a hash table as a data structure?
- How do you get back to the original binary search tree if the nodes have been switched?
- How can you tell if a binary tree is really a binary search tree?
- Can you change each key in the binary search tree so that it holds the sum of all the keys that are bigger?
- Do you prefer building a binary tree from a postorder sequence or a preorder sequence?

**Examples of how to answer questions about the binary tree in an interview**

Employers ask different questions of job applicants to find out important information that might not be on their resumes. Take a look at these binary tree interview questions and answers to learn how to give short, clear answers:

**Have you ever had a big problem to solve at work? How did you handle it?**

When an interviewer asks you this question, be honest and direct, because problems are common in many workplaces. The way you handle problems shows interviewers that you have the skills and willingness to handle a wide range of situations well. Keep your answer short and only mention the most important things. Stay professional during the whole interview, and don’t talk about problems; instead, talk about how to solve them.

Example: “At my last job, I was given two binary trees and told to check if their structures and node values were the same. This was very hard for me, but I figured it out by doing a preorder that goes through both trees and checks to see if the nodes on both trees are the same. I first solved the problem using an iterative method, and then I used a recursive method.”

**2. Tell us about a time when you failed.**

To answer this question, try to think of a real, true failure and tell the interviewers how you define failure. You could say you failed if you couldn’t finish several projects on time or if you had a hard task that took longer than usual to finish. Make sure you know how the choices you make will help you in the long run.

Example: “I tried many times while working on a project to figure out how to make a binary tree from the given order and depth-first search, but I couldn’t figure it out. At first, it didn’t seem important to finish the task, but I kept looking for other ways to do it and asking other colleagues for help. Soon after that, my boss came to my desk and we both saw that the data was wrong. We started over with the right information, and it only took a few minutes to finish the job.”

**How do you add up all the numbers in a binary tree?**

Interviewers might ask you this question to see how well you can solve problems and make decisions. This question also shows how well you know the job and how much you know about it. When you answer, give a detailed explanation of how to do the process to show how flexible you are in the field.

Example: “Assume that the value of an empty child in a binary tree is 0. Then, replace the value of each node with the total number of elements in its right and left subtrees. Use a recursive method to change the right and left subtrees, and then use a postorder tree traversal to change a node. Update the value of each node so that it is equal to the sum of the elements in its right and left subtrees. Then, from the function that figures out the node’s value, reverse the sum of all the elements in the subtree that the node is the root of.”